Solderless lug



May 5, 1959 A. R. NQRDEN 2,885,654 SOLDERLESS LUG Filed Jan. 25, 1954 FIG. 2

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ATTORNEYS SOLDERLESS LUG Alexander R. Norden, New York, N.Y., assignor to Federal Electric Products Company, Newark, N.J., a corporation of Delaware Application January 25, 1954, Serial No. 405,889

3 Claims. (Cl. 339-272) My invention relates generally to connectors and coupling members and especially to connectors for electrical wires or cables and more specifically to connectors of. the screw clamp, solderless type.

One object of the invention is to provide a solderless connector which is rugged and durable and yet simple and easy to manufacture.

Another object is to provide a solderless connector which may be punched from strips of fiat metal stock and which requires a minimum of machine operations.

A still further object of the invention is to provide interlocking means for said connector which will enable the connector to resist any tensile stresses which may result from the wire-clamping operation. Another object of the invention is to provide a connector which aifords an efficient electrical connection as a result of a very tight mechanical clamping action.

The above and other objects, features and advantages of the present invention will be more fully understood from the following description considered in connection with the accompanying illustrative drawings.

In the drawings which illustrate the best mode presently contemplated by me of carrying out the invention:

Fig. 1 is an enlarged perspective view of the connector, the wire clamping screw being omitted;

Fig. 2 is a sectional view taken along line 22 of Fig. 1 and showing the cable clamp within the connector and further showing the connector clamped to a bus bar or the like;

Fig. 3 is a bottom view of my improved connector;

Fig. 4 is a plan view of a strip of fiat stock from which the connector blanks may be punched;

Fig. 5 is a plan view of a single connector blank; and

Fig. 6 is a sectional view of a modified form of my invention.

The connector 10 as illustrated in the drawings is formed from a metal blank punched or otherwise formed from a flat metal strip illustrated at 12 in Fig. 4. In my preferred embodiment the connector is formed of copper but this is not to be taken as a limitation with regard to the material employed. A single metal blank 14 is illustrated in Fig. 5. It will be noted that this blank is generaly of flat rectangular form but has complementary male and female portions at the opposite ends thereof, designated generally by reference numerals 16 and 18, respectively. The male portion or projection 16 comprises an inwardly, concavely curved neck portion 20, outwardly extending shoulder portions 22, and an arcuate head portion 24 bridging the outer extremities of said shoulder portions.

The female portion 18 has a curved edge 25 which lies close to the curved edge 24 of the male portion 16, and all other edges of portions 16 and 18 are close to each other in the connector 10. In other words, portions 16 and 18 are constructed and arranged to interfit with each other and form a secure interlock between the ends States Patent of the blank when the latter is bent into the connector formations illustrated by Figs. 1 to 4.

As will be obvious from Fig. 4, when these blanks are punched from a strip of flat stock, the male and female portions will automatically and simultaneously be formed and there will be no scrap or other waste of material. The blank 14 is formed into the connector 10 by bending the blank at the transverse lines indicated at 26, 28, 30 and 32, respectively, and the areas between these lines are indicated for convenience in description as 34, 36, 38, 40 and 42. Areas 36 and 40 have formed therein apertures 44 and 46, respectively. These apertures are each internally threaded as illustrated at 48 and 50 in Figure 1. The material adjacent these apertures may be extruded as shown at 52 and 54 respectively in Figure 2. This, of course, provides a greater threaded surface and lessens the danger of strippage of the threads. It will be noted that the bottom extrusion 54 is square at its external periphery as shown clearly in Figure 3, but if desired this extrusion may be circular.

It will be readily apparent that when the blank is bent along the four previously described lines it will form a. member with a peripherally continuous side wall, as illustrated in Fig. l. The section 36 becomes the top wall of the enclosure, the section 38 becomes one of the side walls, section 40 becomes the bottom and sections 34 and 42 interlock to form the other side wall. It will be noted that member 10 is completely open on the other two sides and that either of these open sides may be utilized to introduce the Wires or cables 56 which are to be connected. Referring now to Fig. 2 it will be seen that screw 58 threadedly engages the aperture 44 and acts as a clamping element to securely retain the cable 56 in position within the connector while at the same time insuring that sufiicient electrical contact is established. The screw 60 threadedly engages the aperture 46 and is utilized to clamp the connector 10 to the bus bar or metal conductor 62. The latter is provided with a square hole or recess in which the extension fits so that connector 10 is held against rotation and positioned as desired in relation to the bus bars 62.

The embodiment illustrated in Figure 6 is similar in all respects to the preferred embodiment of Fig. 1 with the exception of the fact that instead of introducing the wires or cables through the open sides of the enclosure, an aperture 64 has been formed in wall 38 for receiving said wires or cable. The advantage to this particular construction resides in the fact that the cable is more firmly held in position, but, of course, the overall structure is somewhat weakened by the additional hole.

Particular attention is directed again to applicants novel interconnecting means constituted by interlock members 16 and 18 provided in the interlocking end portions 34 and 42. Not only are these interconnecting means easily assembled, but they also result in a joint which offers maximum resistance to tensile stresses which may be set up in the side walls as a result of tightening of the screw 58 where the wire is secured in the connector. Noting particularly Figure 1 it will be seen that any tensile stresses which would tend to force the sections 34 and 42 apart from each other are directly opposed by the shoulders 22.

Further, it will be observed that by reason of the curved edge 25 in the portion 18, more metal is provided in portion 42 at the lower side portions 18a of interlock member 18 than if the inner edge of portion were defined by straight lines; and this additional metal increases the resistance to the forces tending to spread the sides 18b away from each other by the forces applied to shoulders 66 of interlock member 18 by the shoulders 22 of interlock member 16 when the clamping screw 58 3. is forced against the wire in securing the latter in the connector 10.

While I have shown and described the preferred embodiment of my invention, it will be understood that various changes may be made in the present invention without departing from the underlying idea or principles of the invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A solderless rectangular electrical connector for a conductor, comprising a pair of opposed side walls and a pair of opposed top and bottom walls, one of said side walls comprising mating male and female interlock elements, said walls and saidinterlock elements constituting one integral metallic strip, said interlock elements being disposed in coplanar relation and together constituting approximately halfof said one of said side walls, said top wall having a threaded opening, a screw threadedly engaging said threaded opening and arranged for clamping said conductor against said bottom wall when said conductor is inserted between said top and bottom walls, the,

ing oppositely extending shoulders extending parallel to said top wall and said female element having a conformation completely complementary to said male element including transverse shoulders abutting the shoulders of said male element.

2. A solderless connector in accordance with claim 1, wherein said conductor is clamped by said screw against the inside surface of said bottom wall of said rectangular connector and wherein said metallic strip is of copper for providing a path of good conductivity from said conductor to the outside surface of said bottom wall, said bottom Wall having a threaded opening for receiving a screw to hold a bus bar against said outside surface of said bottom wall, said conductor being. thus connected by said connector to said bus bar.

3. A solderless connector in accordance with claim 1 wherein the side wall opposite said one wall that comprises said interlock elements has a conductor-receiving opening.

References Cited in the file of this patent UNITED STATES PATENTS 438,822 Philion Oct. 21, 1890 2,077,688 Gottlieb Apr. 20, 1937 2,145,556 Rypinski Jan. 31, 1939 2,173,206 Landmeier Sept. 19, 1939 2,232,857 Jackson Feb. 25, 1941 2,283,918 Dekome May 26, 1942 

